" A 5-year–old boy, born of non-consanguineous marriage presented with large head, seizures, mental retardation, delayed mental and motor milestones."
A 5-year–old boy, born of non-consanguineous marriage presented with large head, seizures, mental retardation, delayed mental and motor milestones.
There was no history of seizures or myoclonic jerks.
Examination revealed short stature, macrocephaly and mild cognitive impairment.
Diffuse supratentorial subcortical and deep white matter hyperintensities on T2 and FLAIR sequences with subcortical cysts in anterior temporal and frontal lobes (blue arrows). Relative sparing of internal capsule (star) and grey matter structures.
DIAGNOSIS:
Megalencephalic leukoencephalopathy with subcortical cysts aka Van der Knaap disease
DISCUSSION:
- It is a rare inherited autosomal recessive disease characterized by diffuse subcortical leukoencephalopathy associated with white matter cystic degeneration.
- First described by van der Knaap et al. in 1995.
- Disease has a high incidence in Agarwal community in India and Jewish community with consanguinity being a high risk factor.
- MLC is an autosomal recessive disorder due to mutations in MLC 1 gene7 which has its locus in chromosome 22qtel. The diagnosis of MLC can be made with confidence in patients with typical clinical findings and characteristic abnormalities on cranial MRI.
- Almost all patients have seizures from an early age. Early development is normal or mildly delayed. Slow deterioration of motor functions with cerebellar ataxia and mild spasticity usually starts in early childhood.
- Diffuse supratentorial symmetrical white matter changes in the cerebral hemispheres with relative sparing of central white matter structures like the corpus callosum, internal capsule, and brain stem; and grey matter. Subcortical cysts are almost always present in the anterior temporal region and are also frequently noted in the frontoparietal region.
- Differential diagnosis of MLC includes, Alexander disease, Cystic leukoencephalopathy without megalencephaly, Vanishing white matter disease, Canavan’s disease and Glutaric aciduria type 1.
Dr. Sriram Patwari
MD, PDCC (Neuroradiology)
Consultant Radiology, Co-lead Neuroradiology
Manipal Hospitals Radiology Group
Dr Vikas H P
DNB resident
Manipal Hospitals Radiology Group
